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