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