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