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