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