One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(9,10,14,18)(11,19,21,15)(12,22,23,16)(13,17,20,24)(25,26,30,33)(27,34,29,31)(28,36,38,32)(35,39,37,40)(1,3)(2,6)(4,7)(5,8)(9,11,14,21)(10,15,18,19)(12,13,23,20)(16,17,22,24)(25,26)(27,31)(28,32)(29,34)(30,33)(35,39)(36,38)(37,40)(9,12,14,23)(10,16,18,22)(11,20,21,13)(15,24,19,17)(25,27,30,29)(26,31,33,34)(28,37,38,35)(32,40,36,39)(2,4)(6,7)(9,12)(10,16)(11,13)(14,23)(15,17)(18,22)(19,24)(20,21)(25,28,30,38)(26,32,33,36)(27,35,29,37)(31,39,34,40)(1,4,5,2)(3,7,8,6)(9,13)(10,17)(11,12)(14,20)(15,16)(18,24)(19,22)(21,23)(25,29,30,27)(26,31,33,34)(28,35,38,37)(32,40,36,39)(1,3)(2,7)(4,6)(5,8)(9,10)(11,15)(12,16)(13,17)(14,18)(19,21)(20,24)(22,23)(25,26)(27,31)(28,32)(29,34)(30,33)(35,39)(36,38)(37,40) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.