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