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