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