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