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