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