One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,8)(4,6)(5,7)(9,10,15,17)(11,18,12,16)(13,14,23,24)(19,22,21,20)(25,26,30,33)(27,34,28,31)(29,37,38,32)(35,39,36,40)(1,3,5,6)(2,4,7,8)(25,26)(27,34)(28,31)(29,32)(30,33)(35,40)(36,39)(37,38)(9,11,15,12)(10,16,17,18)(13,19,23,21)(14,20,24,22)(25,27,30,28)(26,31,33,34)(29,35,38,36)(32,39,37,40)(1,2)(3,8)(4,6)(5,7)(9,12,15,11)(10,16,17,18)(13,19,23,21)(14,22,24,20)(25,26)(27,31)(28,34)(29,32)(30,33)(35,39)(36,40)(37,38)(1,2)(3,4)(5,7)(6,8)(9,13)(10,14)(11,19)(12,21)(15,23)(16,20)(17,24)(18,22)(25,28,30,27)(26,31,33,34)(29,36,38,35)(32,39,37,40)(1,4)(2,6)(3,7)(5,8)(9,14)(10,13)(11,20)(12,22)(15,24)(16,19)(17,23)(18,21)(25,29)(26,32)(27,35)(28,36)(30,38)(31,39)(33,37)(34,40) 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.